The detention of Regivaldo Pereira Galvão, aka as Taradão (Big Pervert), 42, at his home in -Altamira, in the Amazon state of Pará, could lead to the reopening of the case in the death of nun Ms Stang, 73, who was shot in February 2005 amid a dispute with ranchers over land she wanted, brought under government protection.
Prosecutors say Galvão and another rancher hired men to kill Ms Stang over the disputed Amazon land. Galvão, who denies any role in the missionary's death, was arrested in 2005, but he was freed on bail by Brazil's Supreme Court in 2006 and he has since used appeals to avoid trial.
Galvão has denied any role in Stang's death, arguing he had no interest in the lands Stang was defending.
But prosecutors say that in November he went before Brazil's Incra land reform agency to present documents showing he owns the disputed land and wants it back – casting doubt on one of his main defenses.
A second rancher accused in Stang's murder, Vitalmiro Moura, was sentenced to 30 years in prison in May 2007. But Moura's sentence was overturned earlier this year after a gunman confessed to killing Stang and said he acted alone. Gunman Rayfran das Neves Sales was sentenced to 28 years in prison.
Stang was born in Dayton, Ohio, and spent three decades trying to preserve the rain forest and defending the rights of poor settlers who confronted powerful ranchers seeking their lands in the Amazon's wild frontier.
Mercopress